Gap between 2 floors

[Plunk13]

I've just removed an interior wall to open up the kitchen/dining area. There was a drop where the wall was, but that was filled in by the builders.
Now there is still a gap between the two floors. The tiles on the one side won't be removed - they are at around 15mm height. On the other side the laminate is around 8mm in height.

Any suggestions on the best way to fill the gap at a slope? Simple sharp sand/cement mix?
I will probably put down some laminate tiles on the kitchen side, so no additional screed on top.

 

[Plunk13]

Unfortunately I can't do that because the 2 sections of concrete are not level. It's not obvious looking at the pic.
On the other hand, would it work if I used tiles that were around 5mm in depth (those red tiles are 12mm approx), then just built up a gradient of mortar from one side to another- the uneven surface wouldn't matter too much?

 

[Plunk13]

Sand and cement won't work. It'll just break up it won't be deep enough.

You can get some ready to lay latex and trowel to whatever level you like.

Oh, that looks promising. I'll have a google. Thanks for the pointer!